1. Field of the Invention
The present invention relates generally to a centrifugal separator and more specifically to a centrifugal separator having a spin post extending beyond the spin plate thereof.
2. Background
Centrifugal separators are well known for separating solids from flowing streams of water in which they are entrained. The classical arrangement is to inject the stream from a nozzle tangentially into a cylindrical separation barrel. As the stream whirls around the wall of the separation barrel, the high g forces within the stream cause the solid particles to migrate toward the wall as the whirling stream flows from an upper elevation to a lower elevation in the separation barrel. At or near the lower end of the separation barrel there is a spin plate that reflects the central portion of the tubular-shaped whirling stream upwardly toward a central exit port. This central portion of the stream is substantially free from solids in a properly designed and properly operated centrifugal separator.
Solids nearer the wall of the separator barrel pass through a slot near the spin plate, either through or at the lower end of the separation barrel. These solids form part of the out portion of the stream, which is contiguous to the wall.
Separation devices of this type are frequently used to separate solid particles over a large range of sizes. Devices using these principles range in size from as small as parts cleaners for use in automobile service bays, to large factory installations for separating crop washings and floor sweepings from wash water, to removal of grit from very large water distribution and irrigation systems.
Such systems are generally passive, and the function and efficiency of the system derives in large part from the velocity and smoothness of the flow of the stream in the separator. Turbulence anywhere in the system, or inefficiency in the introduction of the stream into the separation barrel, will result in the need for more power (higher injection pressure), or a reduction in the efficiency of separation.
Existing centrifugal separators may include a spin plate for aiding rotation within the separation chamber. In some cases, however, the vortex created within the separation chamber moves away from the center of the spin plate. This is particularly true at lower flow rates. Further, particles may enter the central region of the vortex within the separation chambers, and once particles enter that region it is difficult to remove them before they leave the top of the separation chamber.